I haven’t used the consumer version, so I don’t know what it is capable of (although there is a thirty day trial available 🙂 ). Here is a feature set for it.
As for another program for authoring DVD’s, yes there are several. However, I would recommend you get a license transfer from another DVDA user (for instance you could buy 4.0, or 4.5 if they are not using them). You cannot upgrade from it- that is the only limitation.
Another option would be Nero, but I would recommend giving the consumer version a go or sell your copy of Vegas pro8 and bite the bullet. I think the copy you have is from Tigerdirect.com or BHPhotovideo.com where they have their own offering of the product. I don’t know how they get to separate the product, but they do.
I hope this was helpful.
j razz